. >> president obama has thrown the switch, lighting the national christmas tree. michelle obama and their daughters joined the president on stage as he counted down. the president did a little dancing with a little elf. the festivities wrapped up in pretty hua weather there in washington. >>> meantime, a bay area family is one of 20 in the nation competing in the great christmas light fight. >> my collecting of disney got to a point where i felt i had enough holiday disney characters and mickeys et cetera that we decided to set up a display and incorporate my disney collection with our christmas decorations. >> now there is a fan. the great christmas light fight will air right here on abc7 starting next monday. stay tuned. >>> help us feed the bay area this holiday season. visit the facebook page and take the pledge to give where you live. we will donate $1 in your honor to the bay area's feeding america food bank up to $75,000. everyone who takes the pledge will be entered to win $7,000 cash. the winner will be announced on december 19th. >> one of the great thin